Sicklefin Weasel Shark

About the Sicklefin Weasel Shark

Sicklefin Weasel Sharks are known for their sickle-shaped fins that have white tips. 

They can be found in the Indian Ocean and western central Pacific Ocean near countries such as China, India, Malaysia, Myanmar, the Philippines, Sri Lanka, Taiwan and Thailand.

Biology and Behaviour

They have round, moderately long snout, but a short mouth. Their eyes are relatively large with nictitating eyelids to help protect their eyes from particles and to keep them moist. They have small spiracles to supply oxygen to their eyes and brain and short gill slits. Their upper teeth have distal cusplets and their lower teeth are shaped to inverted ‘Y’s. 

Sicklefin weasel sharks swim in shallow waters of 170 m/557.7 ft deep. They mainly feed on cephalopods such as octopus, cuttlefish and squid. They will also eat crustaceans and echinoderms.

Reproduction and Lifespan

Sicklefin weasel sharks are viviparous, meaning giving birth to live young.. Females give birth twice a year due to their gestation period of only six months or less. They have an average of four to eight pups per year per with a litter size between two and four. Young sicklefin weasel sharks are 47 cm/1 ft 6.5 in at birth and can grow to 114 cm/3 ft 8.9 in long. Males reach maturity at approximately 75 cm/2 ft 5.5 in and females just a little longer at 75 cm to 78 cm/2 ft 5.5 in to 2 ft 6.7 in.

Conservation and Tourism

Since sicklefin weasel sharks are not as productive as the closely related Australian weasel shark, they cannot withstand the fishing pressure. The IUCN had first assessed sicklefin weasel sharks least concern in 2003, but because of fishing exploitation, these sharks are now vulnerable because of its decreasing population.

Sicklefin Weasel Shark is caught in coastal fisheries by demersal trawl, tangle nets, set nets, gill nets, droplines, longlines, and Danish seine (White et al. 2006, Blaber et al. 2009). It is taken as retained bycatch in industrial and artisanal fisheries. In India, there is high level of fisheries exploitation with most stocks fully exploited (FAO 2020b). Juveniles are found in estuaries and high fishing effort, particularly with stake and doll nets, occurs in this habitat. The majority of the geographic distribution of this species in the region overlaps with intense coastal fisheries. The meat is used for human consumption fresh or salted and dried. Heads and other discarded parts may be used as fish bait in traps (A. Bin Ali unpubl. data 2020). In some cases, shark jaws and teeth are cleaned and sold as souvenirs (Department of Fisheries Malaysia 2006). In Malaysia, small sharks, such as this species, are sent to fish mill factories and used for fertilizer.

There are currently no conservation actions in place for sicklefin weasel sharks.

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Sicklefin Weasel Shark Gallery